Posted
by
timothy
on Saturday April 24, 2010 @10:26PM
from the in-his-unbiased-opinion-of-course dept.

HaymarketRiot writes "Richard Branson has claimed that the flight ban, due to the eruption of the volcano Eyjafjallajokull, was an overreaction on the part of the authorities. Britain's government has even called for the airlines to be compensated. This does look like a perfect excuse for already greedy airlines to try and get more money ... any experts care to comment on the effect of volcanic ash on planes?"

Basically, the jet's internals are hot enough to melt rock back into glass... So after a couple of passes through ash clouds, you have a thin layer of glass covering all the internal turbine blades. Which completely destroys the engine, and is extremely hard to repair without completely replacing the blades.

So, basically, what I've been told is that, yes, flying a jet through a volcanic ash cloud is a good recipe for completely destroying the engines, such that they need to be rebuilt, within two or three passes through the ash. It sounds plausible, and I've not yet heard anyone who actually does aircraft maintenance or anything like that suggest that it's harmless.

There's some uncertainty over [bloomberg.com] the level of ash that poses a significant threat, though. What's known is that zero ash is fine, and a lot of ash causes significant damage, but not too much seems to be known about the concentration/response curve beyond that.

Of course, it's also pretty clear that Branson is angling for a handout here, not really deeply interested in science or public policy. He has a pretty big self-interest in convincing people that the cause of the shutdown was government overreaction, in which case the government should compensate the airlines; rather than having people believe that the shutdown was a necessary reaction to the volcanic eruption.

Branson needs to live up to his manly man self-image and fly through highly concentrated areas of the ash clouds himself (alone).
I would contribute money for a cheap funeral for his ashes, based on the payout of a death pool of course.
Look at what the Finnish Air Force found out about the sustainability and safety of flying through this stuff. Not safe practices.

That's an apple-oranges comparison. The video shows a GE-Honda HF120 turbine [wikipedia.org], a 2,000 lb two-stage, two-compressor turbofan designed for the light jet market. A very different design from...

Aside from that, the difference in scale of a fine volcanic ash particle compared with a grain of sand determines the melt rate. Volcanic ash passing through a turbine is essentially a fluid, one that melts at around 1000 C. Aggregate sand (in the video) melt between 1500-1700 C.

Turbofan combustion chambers burn at between 1500-2000 C. Grains of sand are too thick to melt, given the airflow rate through an engine (250-1400 mph.)

The engine isn't the only important part of a jet aircraft. Apparently flying a jet aircraft through what's effectively 200 miles of sandblasting has other deleterious effects such as sandblasting the windshield, abrading the skin of the wing and other forward parts and trailing parts including the tail, obstructing the pitot tubes that gauge airspeed. Some of these effects are immediate and inconvenient (landing an aircraft when the windscreen is frosted glass can be challenging), and some are not immediately apparent but can cause aircraft failure several months after the ash is gone. Trailing edge surfaces can also be affected in subsonic aircraft, though these can be less important because critical control lines can not be routed aft of trailing edge surfaces. The mobility of ailerons and flaps can be affected by grit. This grit can cause failures in flight because the maintenance schedules for aircraft do not account for flying through powdered glass.

Let's review: Glass is harder than steel. Volcanic ash is glass. Volcanic ash in the air can be as course as 1.5", or as fine as 60 microns. The skin of aircraft are predominately aluminum. Aluminum is not as hard as steel. These ash particles can abrade aluminum. If you fly though enough abrasive, the skin of your aircraft will wear through.

The way airlines work some of these aircraft might be rotated to routes far from northern Europe, placing almost anyone at risk. Did that commuter plane from San Francisco to San Diego accumulate ash damage over the North Atlantic? You don't know.

It's better safe than sorry I think. We have a long history of airlines ignoring common sense and basic safety to put butts in the seats. They need regulation to keep them from getting stupid.

It's not like volcanos were just recently discovered. They predate airlines by a good bit, and Iceland volcanos go off on a regular basis. I say it's part of the normal order of the day for these airlines. If they're not insured against this risk then it's their own cost because they're self-insured. I'll bet some of them are getting compensation from their insurance and want to be compensated twice to improve their bottom line. Getting paid twice to not carry passengers is almost three times as profitable as getting passengers to grandma's house - especially if Grandma's house is in Finland, since they save some accellerated depreciation on a very expensive aircraft.

I don't know about Branson, but some of the airline CEOs did go up on one of those successful test flights they sent up Sunday through, I think, Tuesday after eruption. It still took those regulators days after that too lift the senseless ban.

They was just publicity stunts of no scientific value at all, especially given the majority of the flight time was well above the ash cloud. If they had spent hours up there flying at various speeds and altitudes and covering large swathes of Europe it might have meant something.

Of course, fortunately, the original question is easy to answer as there was no over re-action because they had to no choice. It is the law. You do not fly through volcanic ash. Maybe some research could be done on concentrations of volcanic ash that pose a threat and the law subsequently changed but as it stands, the right thing was done.

Lufthansa did not send up ten flights. There was one German flight that flew a flight that increased in altitude by 1000 feet every ten minutes or so up to 40000 feet. At the time the cloud was estimated to be about 15000 up in the air. The CEO was on the flight and no instruments were on board to say what concentration of ash they were flying through. For all anyone knows they weren't flying through any.

You may be confusing the number of Lufthansa flights with the 50 that were given special permission

He is also going to be screwed by his engine repair facilities. Most airlines operate a 'power by the hour' arrangement for their engines with an Engine Overhaul facility (Maintenance Repair Organization (MRO) where they pay a fixed amount per flying hour. This comes with many conditions including "thou shalt not fly through volcanic ash".

Come time to send the engine in for overhaul (after about operating 30,000hrs) if there is sufficient evidence of turbine erosion that can be attributed to volcanic ash then the airline will be stuck with the US$7M per engine invoice. My college (who deals with engine health monitoring and MRO's) reckons a medium sized airlines may be in the hole for US$2B should they're engines be exposed to ash.

Branson is being a doosh on this one, and should thank his lucky stars the regulators kept him out of the sky.

The engine makers set the limit at 0, many years ago. The airlines were asked if they wanted a review of that in 2008. They ignored that offer, so it is the airlines fault, pure and simple.
Any other argument is just posturing.

While I know next to nothing about planes or volcanoes, I do know that volcanoes erupt along the pacific rim all the time, without the airspace of an entire continent having to be closed for a week. Apparently the authorities in the US just issue an advisory, and airlines just fly around the worst affected parts. Branson isn't the only airline director who went to the media saying that the flight ban went on far longer than was necessary, and that they fly through some levels of volcanic ash or desert dust every day.

I think the "explosive" type of volcano that can hurl concentrations of ash into the air is just one specific type. I would guess that it's like Mt. St. Helens in that a magma flow encounters significant resistance, pressure behind it continues to build, and eventually the pressure reaches a point where the resistance is overcome suddenly and catestrophically, causing a huge explosion. By comparison, volcanoes like those in Hawaii tend to erupt frequently, and when they do, quantities of liquid lava well up from the ground and no sudden explosions or launches of ash take place.

I am definitely not a volcanologist or a geologist. Having said that, it's possible that the kind of eruption that causes problems for airplanes is only one possible event of several or many possible events and may be a rarity.

The difference here is that a volcano like the one on Hawaii does have frequent eruptions and the amount of water absorbed into the rock is low, but with volcanoes that seldom erupts and/or are located under glaciers you will get a lot of water involved which tends to create a fine dust cloud of the ash that spreads easily.

The real culprit here is in fact water! When pressure drops you will get a chain reaction where water goes from liquid to gas form in a moment which results in several things; A quick cooling of the rock to solid state (transiting from liquid to gas costs energy), intense expansion of the mixed mass of lava/steam causing a powerful eruption and as the rock was rapidly cooled it will be brittle and easily cracked into very small particles that easily stays in the atmosphere for a long time.

Now - this dust is essentially really fine sand particles, and when you fly through them they will sand blast the aircraft, but also they will melt in the jet engines possibly extinguishing the flame and cause deposits in the turbines. Under some conditions (depending on throttle of the engine, engine type and composition of the particles) they will not melt, but just sand blast the engines essentially acting as an engine cleaner - however since there are too many unknowns involved so you can't count on that.

Anyway - engine damage to aircrafts is the major reason for the "No Fly" directive - an aircraft without engines will sooner or later make an unplanned landing and those are usually messy. Secondary issue is that the windshields of the aircrafts get sandblasted too so the pilots may have a hard time see what's in front of the aircraft. Missing the runway won't be good and make a mistake when taxing is embarrassing to say the least. Decreased view while in the air isn't that much of a problem as long as you have your instruments.

Yes, I'm sure Boeing is really in a hurry to issue a public statement saying 'we accept liability for loss of life and damage to aircraft if it turns out that flying in the current conditions is dangerous.'

I remember seeing something about this on Discovery or History channel years ago and a quick search pointed me to British Airways Flight 9 on Wikipedia, all four engines FAILED!

BA Flight 9 flew through a concentrated ash cloud, and no-one is saying that aircraft should do so. But there's a level between that concentration and zero where the ash causes no significant impact on the engines, at which point it's safe to fly; more than that, there are higher levels where the engines will require increased maintenance but the airlines may be willing to pay that cost in order to keep the planes flying.

The idea that a tiny level of ash will cause an airliner to fall out of the sky is just

And to go along with your post, the British Airways flight was about 100 miles from the volcano, and all 4 engines started up again after they were out of the ash. One of them failed again, but they were able to make it safely to an airport on their own power rather than strictly gliding.

I thought the travel blackout was a little too knee jerk. I don't know how high the ash got in the atmosphere, but I'm thinking that there would be a more or less safe zone either above or below the main concentration of

And to go along with your post, the British Airways flight was about 100 miles from the volcano, and all 4 engines started up again after they were out of the ash. One of them failed again, but they were able to make it safely to an airport on their own power rather than strictly gliding.

After one of the longest glides in history in a regular aircraft, and landing instruments-only because the windshield was rendered almost opaque from the ash, and even then with half the instruments out of commission.

Given the history of aircraft encounters with volcanic ash clouds - near disaster every time, averted only by heroic efforts by the pilots - the total shutdown was the only appropriate short-term response.

I think it's worth specifying that the wind screen becoming opaque wasn't from ash sticking to it, but was from the ash sand-blasting it. It had the same effect on the landing lights and with this incident happening at night, added yet another level of difficulty to the situation.

The airspace belongs to the people. The airlines get to use the airspace with the permission of the people. The government represents the people. If you don't like it, establish a sovereign nation and treaties with international air travel authorities to do what you want as high as you like over your land.

If you think that being stuck in a safe first world country for a few days is problematic, you are far too sheltered. You took the risk to fly there for profit or pleasure, and no-one owes you a guaranteed safe passage anywhere. Notice that big blue expanse? Or those two parallel lines leading you out of Europe? If you wanted to take the initiative instead of bitching, you could have been anywhere on earth within a few days. But it's far easier to believe someone else is responsible and sit back while they fix your problem.

On the matter of 11/9, living in Britain near London I've survived the decades of pIRA attacks. We evacuated the area and returned within a few hours each time. The whole city was never closed for 3 days because we didn't have an irrational fear of potential unpredictable harm, whereas we know fairly well the action of ash in a jet engine and on cockpit glass.

This is a knee jerk reaction to being stuck in Frankfurt longer than you wanted. If you do not know how much ash brings down a plane, do you think it's a good idea to allow planes to fly through the stuff?

The "test" flights by a few airlines added nothing to the discussion apart from the fact that it was safe, at that moment, to fly a short time through an unknown concentration of ash, over that particular country and then swan about for a couple of hours 20000 feet above the cloud. I will not fly on those airlines again. They demonstrated total disregard for their passengers by staging a stupid publicity stunt, clouding the waters of a serious technical evaluation and all for commercial gain.

They didn't take passengers up with them but they did say "hey we didn't die on our flight" in order to get public opinion to pressure the authorities into opening the airspace. The fact that the useful data obtained from their flight was as close to zero as makes no difference (and they knew it) was an irrelevance for them.

You saw no volcanic ash because it was microscopic and several thousand feet in the air. The British scientific plane that went up, loaded with specialised instruments that could actually detect volcanic substances in the air and could test densities landed with the pilot saying they had a couple of scary moments. They could smell the sulphur and they wouldn't fly a jet liner up there.

The cloud covered the whole of Europe from Scandinavia down to Northern Italy. There were no corridors that anybody could detect. They may have been there but if you cant find them, you cant fly along them.

I am sorry you got stuck and I probably would have felt more like you in your situation but fortunately these kinds of decisions are not taken by people in desperate situations.

The ferry and train services out of Europe were slammed from the minute the closure was announced. They just weren't set up to handle the sudden demand. The Eurostar has been booked solid ever since, and it still booked to capacity with the backlog of passengers.

It's a great plan to take the Eurostar back - so great that everyone else had the same idea. There's a reason the British Royal Navy has been acting as a ferry service from European ports back to the UK - supply is far short of demand at the moment.

And to go along with your post, the British Airways flight was about 100 miles from the volcano, and all 4 engines started up again after they were out of the ash. One of them failed again, but they were able to make it safely to an airport on their own power rather than strictly gliding.

That's great for 4-engine planes like the 747, A340 and A380. What about the twin-engines used for shorter-haul flights?

I thought the travel blackout was a little too knee jerk. I don't know how high the ash got in the atmosphere, but I'm thinking that there would be a more or less safe zone either above or below the main concentration of ash. Then there is the bigger safe zone away from the main corridor the ash is traveling. They might have needed to make adjustments to flight plans, but I think that they could have had a much smaller no-fly zone. Of course I am not even an aerospace janitor, so what do I know?

There had never been extensive testing done to determine safe levels of volcanic ash, so they could not, on a few hours notice, set up "safe zones" with any confidence. In those same first few hours they also might not have had the detailed maps and analyses of ash concentrations and altitudes that we saw in the days after.

Granted I'm not an aerospace janitor either, but given the little they knew at the time, which included direct knowledge of what can happen when flying near volcanic eruptions (British Airways 9 and KLM 867), IMHO they really had no choice but to issue a complete ban until at least some tests were done without using paying passengers as guinea pigs.

Because you have more engines to fail that makes it safer? The issue is all the engines failing. It doesn't really matter if you have thirty eight engines if none of them are working. The idea that you can glide to safely into Heathrow airport because your engines flamed out at 8000 feet is the kind of thinking these regulators fortunately, do not subscribe to.

We do not know the effects of the volcanic on these planes and we won't know for a long time yet.

I thought the travel blackout was a little too knee jerk. I don't know how high the ash got in the atmosphere, but I'm thinking that there would be a more or less safe zone either above or below the main concentration of ash. Then there is the bigger safe zone away from the main corridor the ash is traveling. They might have needed to make adjustments to flight plans, but I think that they could have had a much smaller no-fly zone. Of course I am not even an aerospace janitor, so what do I know?

I am pretty glad you're not in a position where the life of a LOT of people depends on your decisions.

> But there's a level between that concentration and zero where the ash> causes no significant impact on the engines, at which point it's safe to fly

There probably is. But the problem is that no one knows at what level between zero and BA Flight 9 concentrations (and for how long at that concentration) it is safe to fly. The airlines don't know. Boeing and Airbus don't know. And the jet engine manufacturers don't know. The tests and certifications have simply never been done. The airlines were proposing to do said testing live and in the sky with airliners loaded with passengers. Do you see the problem with that?

The second problem is that, even if it were known that a certain concentration of volcanic ash is "safe" to fly through, it takes specialized and uncommon equipment to measure said concentrations. Said equipment is not carried aboard aircraft. And the onboard radar they do carry detects water droplets in weather formations. Volcanic ash doesn't show up at all. So an airliner flying through a "safe" concentration of ash could be five minutes away from a BA Flight 9 type cloud, and they wouldn't know until the engines shut down.

Sure, just as food tasters are a good way to detect things wrong with the food. Sucks to be the taster though.

"Is he still moving?"

"No."

"Mmmm, I guess this week old fish salad is bad then. Send in the next taster for the running cheese!"

"Don't you mean runny cheese".

"No."

The testing was done by airforces, you know the ones with ejection seats and two engines per passenger? And they considered it unsafe. I take their word for it. If Finland grounds its fighter defence, then I don't go up. I do not know better.

These conditions apparently don't show up enough to justify the cost of determining safe operating parameters. Therefore, no flying. It isn't really complicated -- if a bunch of airlines want to get together and pay for the testing, they can fly. Otherwise, they stay on the ground.

Despite the lack of time, Moody made an announcement to the passengers that has been described as "a masterpiece of understatement":[3][4]“Ladies and gentlemen, this is your captain speaking. We have a small problem. All four engines have stopped. We are doing our damnedest to get them under control. I trust you are not in too much distress.

followed by the gem

"He then called out how high they should be at each DME step along the final track to the runway, creating a virtual glide slope for them to follow. It was, in Moody's words, "a bit like negotiating one's way up a badger's arse"."

The technical people tell you it will all go tits up and everyone spends an enormous amount of time, money and effort making sure it doesn't happen. It then doesn't happen and everybody goes "What the hell did we spend al that money for" despite the fact that it "not happening" is exactly why they spent that money.

The airline response to the shut down of European airspace is exactly the same.

Federal Aviation Regulation 25.1309 relates to airworthiness standards for aircraft, and the fundamental aspect of this regulation is system safety. Excerpt below, with emphasis:

(a)The equipment, systems, and installations whose functioning is required by this subchapter, must be designed to ensure that they perform their intended functions under any foreseeable operating condition.
(b) The airplane systems and associated components, considered separately and in relation to other systems, must be designed so that--
(1) The occurrence of any failure condition which would prevent the continued safe flight and landing of the airplane is extremely improbable, and
[(2) The occurrence of any other failure condition which would reduce the capability of the airplane or the ability of the crew to cope with adverse operating conditions is improbable.

Firstly, Aircraft are not designed to fly through clouds of corrosive silica ash.

Secondly, 'Extremely improbable' is defined in the Advisory Circular (AC 25.1309) to that regulation, which requires chance of catastrophic loss to be less than "extremely improbable" or "1x10^-9" chance of total loss. Techniques such as Fault Tree Analysis are used to allocate reliability of systems to sub-systems, so the entire aircraft can be built from components with realistic reliabilities. However, the volcanic ash offers a 'common mode' failure across all engines including gas turbine Auxiliary Power Units.

The regulators have an obligation to ensure the chance of total loss of an aircraft due to flying through an ash cloud remains 'extremely improbable', i.e 1x10^-9.

Also, if the airlines lost an aircraft because they were allowed to go flying, and were being sued by the families of the victims, they'd be screaming blue murder at the regulators saying they didn't do enough to protect the airlines.

the maintenance of airplanes is the airline's business, not governments.

Sorry, but you're wrong, the governments have the responsibility to ensure their citizens are safe. Keeping airlines in check and making sure they value safety above profits is their task.

Airlines can't simply be trusted to do this by themselves, even if they have the best maintenance routines and model employees [like any business] their decisions will be influenced by shareholders and upper management. Considering the difficult economic conditions for airlines I wouldn't put it past some of them.

If you're American you might have a different view on this, but as a European I trust my government over any business. We [the people] want our representatives to control this and determine when it's safe or not. We like regulations in Europe, it keeps companies in check. The banks in my country were regulated and we avoided the recession that hit the US.

The EU maintains a long list of blacklisted airlines, if the airlines don't hold adequate maintenance standards they don't get to enter European air space. There's obviously a need for some oversight.

That's the problem, I'm not from a major European country. I'm Norwegian. Norway took the correct measures to stave off any negative effects (according to the OECD). Jobs, banks and housing markets remained stable. We have 2.6% unemployment.

While there might be more to the story than simply having regulated our banking industry we did very well during this recession. It doesn't hurt that we're the world's 3rd largest exporter of oil, or that we have no national debt, and put our oil revenue in a huge sovereign fund invested abroad. We base our welfare state on taxes, not on oil revenue.

Part of the reason our banks were already regulated was the fact that during the 1980s Norway had its own bank crisis and housing market crash. The government had to take control of the collapsed banks and rebuild them. Since then our banks have been strictly regulated and the housing market stable.

The UK was badly hit by the recession obviously, but Germany has been out of recession for a long time now. Germany is the major nation in Europe. I believe France technically came out of recession too. Spain, Portugal and Greece are not large countries. I doubt you can find a European country that experienced the recession on the scale of the US.

Dude, maybe you should just stop thinking, because thinking doesn't work very well for you. I mean, 10-20 percent? You are basically saying that you don't have any hard data and just pulling some number out of your arse, then adding that the figure might be twice as high.Well, I've got news for you. In 2008 the unemployment rate in France was at 7.9%. Now the unemployment rate in France is 9.7%, which is exactly the same rate as in the USA.Judging from your other postings here you are just a selfish prick who has missed his flight and had to stay in Frankfurt/Main. Dude, as someone who lives in Frankfurt, I can only say that I am very glad that you finally went back from whence you came. It is people like you who give Americans a bad name.

I'm not nor have I been stranded in an airport as a result of this (nor do I know anyone affected) - so I admit I have no appreciation for how much this is costing travelers and how impatient they are getting.

If a plane had crashed this is what would have happened, and since volcano is still active, I hope this doesn't happen:

1) Public total outrage at the airline(s) that had been flying.2) Even more blame for the airliner that had flow the flight that crashed. The public will blame said airlines' policy and procedures, and probably, the pilot at fault.3) They will blame the government.4) The media will surely get involved in the fiasco they'll tear said airline to pieces.5) Massive lawsuits.5) And, eventually, the airline will probably have to declare bankruptcy since it won't get enough passengers or will be sued to smithereens.

But all is fair here, if an airliner crashes - regardless of if the ash is the cause (a plane can crash for other reasons), there will be massive litigation, (more unfortunately) people will die, families will be upset, and I argue a few airliners might take too much heat and won't be able to stay in business.

Every time I see someone bring up the question of "How much is a life worth?" I recall this event.

Ford was aware of a flaw in design that placed the fuel tank close to the rear bumper. This meant that relatively-low impact rear-end collisions would rupture the tank and set the car ablaze. The corrective action would involved installation of a dividing plate, however they measured the probability of occurence, the amount of potential losses in litigation, and the costs involved and decided that it just wasn't worth doing a recall.

Their reputation took a pretty severe hit, but it has more or less recovered since then(Toyota will be fine too in the end). When you see this, you have to imagine that some companies have made similar cost-benefit analysis regarding human lives and managed to avoid the same kind of publicity.

It can be argued that some companies valued the cost of a human life too little by reducing it to the amount of dollars involved in the lawsuit. Perhaps the cost benefit should be adjusted to involve the value of the life itself. However, when you put that number in, you've already established that there is a price on human life, and from that moment on, you're just haggling over how much.

At some point, there's a limit. Is a human life worth more than 1 million? I think many would say yes. 1 Billion? Probably not as many, but sure there'd be plenty. Multiple-billions? The number of people is going to drop. I think few people would argue that a life is worth 1 trillion dollars (assuming they have any notion of scale). After all, a trillion dollars could probably save many lives, just from the economic externalties alone, let alone what it might do if applied directly to life-saving measures.

Even more simply, calculate the cost of personal luxuries against the amount of donations needed to save a human life somewhere in the world. My American dollars can stretch pretty far in those desperate countries. But ultimately, that's not how I decide how much I give. There's a discount rate involved, not based upon time, but proximity. I'm not necessarily talking about literal physical distance, but mental immediacy. If the person in need is presented to me through video with a detailed documentary about how human this person is, I'm much more likely to sympathize and give money. Especially if that person looks similar to me.

But anyway, I'm not disagreeing with the initial statement by saying that human lives can be priced. An airplane carries quite a lot of people, and I think that number of people being lost simultaneously would certain be more damaging than few billion dollars. The government was just being cautious, which they should be. Those airlines are just fishing for money.

I don't give a SHIT how much you or any other liberal statist fuckwad thinks a "life is worth". The fact is, we lost BILLIONS OF DOLLARS out of our economy and investments. This will DIRECTLY affect the quality of life for tens of thousands of people across the world, and all you god damned statists can think about are ridiculous "what if" scenarios that have proven to be unsubstantiated.

*THIS* folks is why I am a libertarian. No one should have the power to force a company to stop doing business for ANY REASON.

Fuck, I am so angry about this I could scream.

Another piece of evidence for my theory that "libertarian" is just a euphemism for "angry selfish asshole".

We already have evidence of at least one plane nearly crashing due to volcanic ashes. Is this guy saying that we should take the chance? Would he say that to the families of those who could die because of it?

We already have evidence of at least one plane nearly crashing due to volcanic ashes. Is this guy saying that we should take the chance? Would he say that to the families of those who could die because of it?

We have evidence of planes crashing for a wide variety of reasons, some of which were never explained at all. Are you saying we should continue to allow planes to take off when we have reason to believe one will eventually crash? Should any family allow any of its members to ever fly again given that flying is a slightly risky endeavor?/sarcasm

There were also all those military flights [wikipedia.org], especially the Finnish one (pics [flightglobal.com]):

On 15 April, five Finnish Air Force F-18 fighter jets on exercise flew into the ash cloud in northern Finland. Volcanic dust was found on the engines of three of the aircraft and a further inspection revealed extensive damage by molten glass deposits inside the combustion chamber of one of the engines. The engines were sent for disassembly and overhaul. As a result all unnecessary military flights were cancelled except for identification flights to enforce sovereign airspace. Meanwhile a BAE Hawk trainer with special equipment to sample the volcanic dust was being flown from the 41st squadron in Kauhava. Even short test flights with an F-18 revealed engine damage sufficient to destroy engines.

and then also:

On 23 April it was announced that British Royal Air Force training flights had been suspended following volcanic ash damage to the engines of Eurofighter Typhoon aircraft.

Why should I trust commercial airlines which were losing insane money over this, over militaries of several countries?

If you're not sure, and you don't have time to do the tests necessary to make sure, then it's usually best to err on the side of caution. It's very plausible that ash particles and other ejecta could interfere with the normal and safe operation of an aircraft. And you cannot simply pull over and make a pit stop if your aircraft breaks down unexpectedly while you're 10km above sea level - the closest possibility is "pray to god that physics doesn't say you're about to become very, very dead."

This is a barefaced cash grab, nothing more. What were they going to do if it turned out to have a very dangerous effect on the plane anyway, bring the passengers back as zombies and comp them a free flight?

Summary: If you find yourself flying into an ash cloud, turn around immediately.

So, yeah, maybe Branson wants a check, but flying into ash clouds is a very bad idea. And they don't show up on weather radar.

There are thick ash clouds and thin ones. No, you shouldn't have been flying planes in Iceland or northern UK, but halting flights as far south as Turkey certainly seems to have been unwarranted. There is particle-per-million level below which the Boeing bulletin fails to be applicable, and it appears most of Europe was below that level during most of the ban.

and their passengers, not the government.whats next, prison sentences for those who don't rotate their tires?

I take it you are fine with airliners flying without seatbelts and emergency oxygen to save money? In the event of a crash passengers will be free to choose a more expensive airline when they fly again.

Planes are one of the safest means of transportation. This is reached by systematically evaluating all risks. The exact effect of vulcanic ash on the various types of engines seem not to be known. Normally engine failures are not correlated on a signle plane. However there have been examples of planes loosing several (or all) engines at onces when flying trough volcanic ash. This means that this (unknown) risk does not enter in the usual power law for several redundant systems. Moreover its known that in influences sensors of the plane. A loss of sensors caused the crash of the Air France flight some time ago. If several engines fail at once of the sensors fail in a fatal way, people may die.

The logics for this must be: "Do we for sure that a plane can operate as designed under these conditions?" instead of "do we know fore sure its dangerous?"

I dunno. KLM Flight 867 [wikipedia.org] lost all four engines after flying into Mt. Redoubt's ash plume, back in 1989. I was in Fairbanks at the time, and many people I know where stranded, trying to get home for Christmas vacation.

I just did a couple of quick Googles and found that every time there was a mention of the British government accepting that there was an overreaction was a direct quote from Branson. I don't think that he could be considered an impartial source on this quote. I certainly find it difficult to believe that the government is asking for compensation.

And don't the airlines have insurance against this sort of natural disaster?

"Flawed computer models may have exaggerated the effects of an Icelandic volcano eruption that has grounded tens of thousands of flights, stranded hundreds of thousands of passengers and cost businesses hundreds of millions of euros.

The computer models that guided decisions to impose a no-fly zone across most of Europe in recent days are based on incomplete science and limited data, according to European officials. As a result, they may have over-stated the risks to the public, needlessly grounding flights and damaging businesses."

From the Financial Times (http://www.ft.com/cms/s/0/0821cc00-4bb5-11df-9db6-00144feab49a.html?ftcamp=rss)

Where the atmosphere is concerned, every model is flawed for some given value of "flaw". Sure, the dimensions of the ash plume were certainly exaggerated, but how much exaggerated and where?

Knowing you've overstated the aggregate risk to the public doesn't necessarily imply that the groundings were unnecessary, because you don't know *which* groundings averted disasters. Put another way, suppose you know that 90% some set of flights are safe, but you don't know *which* flights. Grounding 100% of those fli

And this flawed computer model grounded me at Frankfurt for more than one week! (And I never planned on being at Frankfurt longer than 2 hours; I was connecting to a flight to London.)

Everyone here who says regulators acted appropriately will surely change their tune if this senseless and groundless overreaction stranded them at a foreign non-destination for a week (more, actually), causing them to miss work and leisure travel alike.

If, at the level of ashes they had over most Europe, it was so dangerous, h

The Google translation clearly shows that Koneiden tultua laskuun koneet tarkastettiin ja moottoreiden imuaukoissa havaittiin perunajauhomaista vulkaanista tuhkapölyä means Machines after the decline in machinery and engines are inspected inlet was observed from potato flour, volcanic ash and dust. They should try it again without the potato flour.;)

That's a really telling translation. It appears as if the Google translator is trying to decipher the sentence in a way that assumes Finnish word suffixes are directly mapped to English prepositions. It saw the "sta" at the end of "perunajauhomaista" and assumed it means "from", and properly translated "perunajauho" as potato flour... Of course, the word is a form of "perunajauhomainen" which is an adjective that basically means "resembling potato flour" that was being used to describe the volcanic "ash dust".

Well go figure when the options are:a) Leave the planes on the ground and lose lots of moneyb) Fly and get expensive damage that'll ground your planesc) Blame the government and get a bailout

He doesn't want to send his planes up there, he just wants money. There's no doubt that many airlines took an extreme financial hit, here in Norway the entire airspace was closed for days and they were losing millions of dollars each day. And that's only counting the direct costs, not counting all the bad experiences pe

99 comments and no one has mentioned:
d) Fly around it
How wide is this ash cloud, anyway?

Several thousand miles, covering most of North-Western Europe. The entire airspace of a long strip of countries was completely closed to all air travel. On top of that, the bulk of the cloud was between 20,000 and 36,000 feet up, which is also where a good chunk of your air travel happens.

When a large number of your international transfer airports are right smack in the middle of a no-fly zone, then it doesn't rea

Not this one. Not a single fatality owing due to volcanic ashes. Yes, there have been a few flights disrupted and a couple flights where all engines shut down and plane maybe had to crash land, but there have been no blood (unless you count scratches that may have happened in crash-landing) for this regulation.

There's a british kid's show called "bang goes the theory" (it's awesome)that had a great little demo of what happens. Basically the ash turns to glass on the hot jet engine turbine blades. It might not be nearly as bad for piston engine planes assuming they have air filters, which is not always the case.

there's a blackhat video here (all I could find) it's the whole show. Luckily the demo is at the beginning. If someone could cut out the pertinant clip it would be cool

> Dutch airline KLM said it flew a Boeing 737-800 up to the usual maximum altitude of 13km (8 miles) on Saturday and Germany's Lufthansa said it flew 10 planes to Frankfurt from Munich at altitudes of up to 8km.

> KLM chief executive Peter Hartman, who was on board the plane, said there was "nothing unusual" about the flight.

I measured the effects of engine ingestion of ash, etc. for several years, and crash/failure rates, for a major military aircraft manufacturer. It was one of our highest priority concerns. As our founder said, we would not build a single-engine aircraft--two at least, to bring the pilot home. Don't underestimate the effect of rocks bashing multi-layer coated alloy blades spinning at X in a plasma. As I told my students, just jump up and down a few times: gravity works.

Aviation safety is not repeat NOT something to play around with. Better for an airline to lose a few million pounds and passengers to be stranded somewhere than for a plane to lose engine power in the middle of the Atlantic.
http://en.wikipedia.org/wiki/Ash_cloud#Aviation [wikipedia.org]

I don't know how many flights were grounded, but I worked on some planes that passed through the cloud. When popping some panels to change the reading lights, I would find small piles of ash (more like gray sand) up inside. Nobody seemed too concerned about it. They probably figured they would clean it up during the next "C" inspection(they tear out the entire interior). And the engines would probably remain until somebody complains about reduced power or high turbine temps or fuel consumption. Now, if you want to really wreck an airplane, fly it through some hail [flickr.com]. And be ready for a tremendous noise.

As ably demonstrated by "Bang Goes the Theory [bbc.co.uk]" on the BBC (UK-only video, unfortunately, but the content is up on Youtube (for now) here [youtube.com]), at Jet-engine internal temperatures the volcanic ash melts into glass, that then sticks to both the turbine blades and the casing, and can cause imbalance and catastrophic failure, but there is a fix! If you turn off the engines and glide the plane through cold air and allowing the turbine blades to cool down, the metal contracts, which is enough variance to shatter the brittle glass and expel it from the engine. However, of course, this involves turning off the engines for an extended period, finding a patch of cold air to glide through, and hoping the glass shatters and is expelled, and that you can get the engines fired back up again, before you get what is referred to in the business as an "Uncontrolled descent into terrain".

It's slightly worse than that, if the blades get covered in glass much at all, they need to be replaced. The problem is that the glass blocks up the cooling channels and they can overheat. Once they've overheated they will tend to creep and fail later.

I find the greedy airlines bit in the summary to be rather offensive. I'm sure more than a few local European airlines will go bankrupt because of what happened. And billions of dollars of potential revenue were lost. Airline companies haven't exactly been rolling in it of late....remember when the high oil prices nearly ran a few of them out of business a year or two ago? These airlines employ thousands of people who are just trying to get by, just trying to make a living, and as companies, they run razor thin margins. And then there are the thousands of travelers who were trapped, burning through their wallets living out of a hotel who couldn't get back home. And the summary basically implies that this is all about greed. This story isn't about greed: it's about survival - people trying to make a living despite a crazy natural disaster that had a very negative impact on many, many people's lives. These people feel like the government was overly aggressive about shutting down air space and didn't sufficiently consider the magnitude of effects it would have on the airlines and the travelers. If the government made a mistake here and it had severe financial implications for lots of people, then government ought to take responsibility for its actions and compensate them.

I live in oregon and maybe 20k years ago we had a volcano blow its top off, mt mazma. covered multiple states in multiple feet of ash. a bit of the eye witness accounts are still around. looks like to me, these things are often troublesome.

I lived in seattle when mt st. helen went. I looked up and saw the plume and chose to immeadiate drive to the closed office and shut the computers down. This was winchester tech, sort of a big platter set, with external air blown in to keep the head up. The ceo wanted to burn me for an assumed failure to protect capital assets in my custody, but had to settle for being mean to my second.

now seattle was never really bothered, but eastern washington got feet of ash drift in places. I hear from the manufacturer hardware techs that a lot of disks had to be completely rebuilt.

so i would say some caution is justified, particularly with life critical tech.

as far as bailouts, nobody owes these stockholders anything. usa tsa budget is already pretty much an airline pr boondoggle.

Shutting down most of Europe's airspace was entirely the right decision. All it would take is one flight through an unexpected dust cloud to produce a near-disaster, if not a crash. That's happened at least five times in the past. Read Boeing's advisory on volcanic ash. [boeing.com]

Read Branson's autobiography? Several times in his life, he's been involved in adventure vacations that left someone else dead. This is not someone you want making risk management decisions for others.

The big problem now is that the airlines are botching the logistics of getting people back where they're supposed to be. [bbc.co.uk] There are people being told they can't get a flight until mid-May, because they booked a flight using frequent-flyer miles or via some discount deal that has a low priority. They can't get the airline on the phone, and they get hit with heavy roaming charges while on hold. This is really tough on people in transit running out of money.

I would like to add that on the near accidents mentioned above the damage to the aircraft was also VERY extensive. The BA flight needed 4 new engines (around U$ 14 million EACH), new windows (more expensive than you would think), new pitot and static ports (and an overhaul of tubing and sensors) and a paintjob (big surface, costs quite a bit) as well as a thorough overhaul of pretty much everything.

Even if no one dies it is still extremely expensive to fly accidentally into an ash cloud.

I really don't think this was an overreaction. Safety must be paramount, and if only one or two aircraft had gone down due to ash that would have seriously impacted the publics faith in the airline industry and their view of safety. That would have been a lot more expensive in the long run, and the airline industry has spend decades building an image of themselves as super safety minded.

And just for the record, I'm an ex-commercial pilot. From Iceland. I've flown smaller aircraft around volcanic eruptions and had great fun.

The cooling system used in gas turbines (jet engines) is very sophisticated and necessary to keep the superalloy blades from creeping too fast. The system consists of bypass air channeled through the blades and exhausted through tiny perforations, creating a layer of cooler air between the blade and the hot flow from the combustor. Furthermore there are two ceramic layers on the outside of the blade. One to prevent oxidation. One to slow heat transfer (insulate). As has been mentioned in other articles, the cooling pores could get clogged by the ash. I also suspect the coating might fail if impacted by ash. If the coating fails or otherwise reacts with the ash, then you can definitely have a problem.

If the blades get just a few tens of degrees hotter, they will surely fail. There's not a lot of margin for error with jet engines. Through good design and manufacturing control, we've managed to make gas turbines extremely reliable, but ash is not a design condition at all. It's abrasive, might react with the coating, and might accumulate on the blades, changing both their mass and aerodynamics.

It's my understanding that volcanic ash is, among other things, incredibly abrasive. Wouldn't flying an airliner through some airborne ash, be like a couple hours worth of sandblasting? I'd hate to think what that does to the engines.

I am not sure that calling the airlines greedy is really fair, the airline industry has been having a very tough time in various different ways since 9/11.

BA in particular have had lots of problems with strikes leading to a negative effect on their already poor finances.

Now I am not saying that they should be compensated, or that it was right for the airlines to want to fly when the conditions could have been dangerous, but "greedy airlines" is probably a little too simplistic.

The chances are that at least one slashdot poster is qualified to comment. Lots and lots of users, topic is a field that many people are employed in, and many of them engineers or techies of some variety.